Right-back Darren Moss was dismissed after 29 minutes for a two-footed lunge and could miss vital play-off games. However, Luke Rogers scored a confidence boosting goal before half time as the ten-men took a lead.
The Shrews also benefitted from a missed Gravesend penalty, Andy Drury blasting over the bar.
Making his debut in the Shrewsbury goal was Joe Hart, who celebrated his 17th birthday on Monday. The rookie turned in an impressive performance, according to boss Jimmy Quinn: 'Joe Hart is 17-years of age and what a keeper he is going to be, he came in and didn't look out of place'.
Quinn also lamented the decision which could see one of his key defenders missing two big play-off games. He said: 'The ref got the decision wrong there's no doubt about that. He was the wrong side of the play and all it was was two players committed to a 50/50 ball on a greasy surface and we will be appealing for the decision'.
There was a rare start for Colin Cramb, though JQ had to remove the strker before half-time to prevent him being sent off. Of the substitution, Quinn said: 'We had to take Crambie off as I didn't want to get another player sent off, I can understand his frustration and we've talked about it and he said it was aimed at the referee because he was frustrated at the decisions'.
Town have secured third spot in the league, meaning they avoid a tricky play-off semi final against Hereford. Town will play either Exeter, Barnet or Aldershot in the play-offs.
With another essentially meaningless game on Saturday, Quinn is set to give his fringe players another chance to play themselves into the reckoning for play-off glory.